[llvm] [OpenMP] Use __builtin_bit_cast instead of UB type punning (PR #122325)

[Joseph Huber via llvm-commits]

jhuber6 wrote:

Only look at the most recent commit, waiting for https://github.com/llvm/llvm-project/pull/122185 to land.

https://github.com/llvm/llvm-project/pull/122325